| Message ID | 1305328729-9995-2-git-send-email-mfasheh@suse.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
Mark Fasheh <mfasheh@suse.com> writes: > This patch introduces a callback in the super_operations structure, > 'get_maps_dev' which is then used by procfs to query which device to return > for reporting in /proc/[PID]/maps. No. It may make sense to call the vfs stat method. But introducing an extra vfs operations for this seems like a maintenance nightmare. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, May 14, 2011 at 08:06:04PM -0700, Eric W. Biederman wrote: > Mark Fasheh <mfasheh@suse.com> writes: > > > This patch introduces a callback in the super_operations structure, > > 'get_maps_dev' which is then used by procfs to query which device to return > > for reporting in /proc/[PID]/maps. > > No. > > It may make sense to call the vfs stat method. But introducing an extra > vfs operations for this seems like a maintenance nightmare. Yeah I'm not thrilled with the extra method either. My concern with using ->getattr is whether it's too heavy since that implies potential disk / network i/o. --Mark -- Mark Fasheh -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 2e7addf..c0acc19 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -220,7 +220,7 @@ static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma) if (file) { struct inode *inode = vma->vm_file->f_path.dentry->d_inode; - dev = inode->i_sb->s_dev; + dev = get_maps_dev(inode); ino = inode->i_ino; pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; } diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index 980de54..6769efe 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -148,7 +148,7 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma) if (file) { struct inode *inode = vma->vm_file->f_path.dentry->d_inode; - dev = inode->i_sb->s_dev; + dev = get_maps_dev(inode); ino = inode->i_ino; pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT; } diff --git a/include/linux/fs.h b/include/linux/fs.h index dbd860a..ad683ad 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1637,8 +1637,16 @@ struct super_operations { ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); #endif int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t); + dev_t (*get_maps_dev)(struct inode *); }; +static inline dev_t get_maps_dev(struct inode *inode) +{ + if (inode->i_sb->s_op->get_maps_dev) + return inode->i_sb->s_op->get_maps_dev(inode); + return inode->i_sb->s_dev; +} + /* * Inode state bits. Protected by inode->i_lock *
This patch introduces a callback in the super_operations structure, 'get_maps_dev' which is then used by procfs to query which device to return for reporting in /proc/[PID]/maps. btrfs wants this so that it can return the same device as it uses from stat(2) calls. Signed-off-by: Mark Fasheh <mfasheh@suse.com> --- fs/proc/task_mmu.c | 2 +- fs/proc/task_nommu.c | 2 +- include/linux/fs.h | 8 ++++++++ 3 files changed, 10 insertions(+), 2 deletions(-)